Ornamental design for a power supply unit



FIG. 1 is a front elevational view of a power supply unit showing our new design.

FIG. 2 is a rear perspective view thereof on a reduced scale.

FIG. 3 is a front perspective view thereof on a reduced scale.

The characteristic features of our design reside in the arrangement of the front panel member as best shown in FIG. 1. 

The ornamental design for a power supply unit, as shown and described. 